My context: 49y/o. Salary: we have a 2-person husband/wife micro-business so "it's complicated" but I pay us £5k GBP ($6.3k usd) p/m so that's ~$80k take-home p/a.
Working hours: absolute max 40 (although I'm taking a day off a week right now to do my own thing), very strict "no evenings or weekends" (apart from site launches and big deadlines of which there are about 3 a year), no work email on phone, long holidays (for example we take August off annually, and do it properly, no email, no phone, no client contact). I think probably I take 30-40 days holiday a year maybe? I don't actually count :-)
We've absolutely, 100% optimised for family. It started off as a semi-deliberate choice and then we moved to Cornwall (for a year, it made us happy so we stayed) and it became more and more clear that being in the now is the focus that makes us happiest. We have 2 teen kids, and we need to be in their lives for the short amount of time (18 years really does fly...) before they leave home and go do their own thing. I have friends who have risen through the ranks of their careers and now pull in anywhere from £150k-£1m++ but every single one of them leaves the house at 7, isn't back before 9 and does it 6 days a week. They employ people to look after their kids, they employ people to clean their houses, they don't know each other, the families are isolated from each other, the kids are fkd up, everyone drinks too much, everyone is intensely stressed all the time... There is absolutely no point, none whatsoever.
I could be dead tomorrow. It could be a speeding car, or a lump, or a mis-step or a stroke. So I try to maximise now. I'd rather have this time hanging out with my family than working (and I love my work - I just don't love it as much as my family!). I know that I'll probably be poor when I'm old, but to be able to eat a meal, sit and chat, go surfing with my kids and wife - I'd make that choice again a million times over.
So - finally - to answer your question. In my humble opinion (and yes, this is opinion, and yes, you have to have some luck - which I have had, at least so far - for these to work...):
1) There's no point in doing work that makes one unhappy. If you've got the choice (and most people do who are commanding north of $100k) then choose a lower salary which gives you more flexibility and life balance than a higher one that doesn't
2) Be in the now. It's all we've got. Sorry to be an old hippy, but it's true.
3) If you can, get a meditation practice going. If you can spare the time, extend this into a week long silent retreat every so often. These give (both) you time to recharge, to consider, to see life in context, to understand that there are bigger things at play than just you.
4) Be fit. It really helps.
5) Eat well. I'd go further with my opinion and say - be vegetarian - but at least minimise your meat consumption.
6) Be with the people you love. Maximise for this time. Everything will end - your life, your friends' lives, your social circumstance. Friends and family are literally the only thing that matters in the end, so make the most of them.
7) Do things that aren't anything to do with screens. Read. Listen to music. Be bored. Walk. Get a dog. Be away from that little rectangle of light for long periods of time.
8) Avoid debt if you possibly can. I'm not talking mortgages - they're pretty much inevitable - but if you can't afford a (luxury thing) then don't buy it, save for it. The people I know who are really, badly in trouble financially are the ones who see a thing and buy it on credit, then it bites them on the ass later.
Good luck out there.